Why the Body Mass Index Is Pretty Stupid

While becoming a teetotaling, vegan, shut-in, marathon runner might well help you to manage your weight, is that a life you'd be willing, or even able, to live with forever? No. Weight loss is about living the healthiest life that you can enjoy.

There is no right way to lose weight, but there are plenty of wrong ways, and what's right for one person is almost certainly wrong for another.

A few weeks ago I got into a gentle and congenial Twitter spat with Rebecca Scritchfield. Rebecca is a registered dietitian, and she's a great fan, and an expert practitioner, of intuitive eating -- using inner cues, not calories, to help guide dietary choices.

Me? I don't intuit my eating as well as Rebecca and so I food diarize every last ounce of food that goes into my mouth. Rest assured, I'm not pathological about it. I don't use my food diary to judge what I've eaten, instead I use it to help guide what I eat, and I teach my patients to do the same. To me, looking at the calories when I eat is akin to looking at price tags when I shop -- and just like price isn't the only consideration when shopping, neither are calories the only consideration when eating. We use food in our lives to both celebrate and comfort, and consequently caloric literacy definitely doesn't always lead to low-calorie choices.

In my Twitter discussion with Rebecca, I had noted that food diarizing protects against mindless eating by allowing for the use of calories in decision making.

Rebecca pointed out that you don't need to count calories to eat mindfully, and that there were other ways of journaling.

So who's right?

Should you intuitively eat, or should you count calories?

And looking at an even larger picture, should you do low-carb, slow-carb or low-fat? Should you include cheat days or no-cheat days? Should there be forbidden foods, or should everything go? These questions could go on and on.

The National Weight Control Registry, the world's largest prospective study of folks who have been successful with long-term weight management, keeps track of the means with which people lost prior to their registration. There's no doubt about it, those folks are good at weight management, with the average registrant having lost about 65 pounds, keeping it off for more than five years. What the Registry has taught us is that while there are some behaviours that are shared by a large majority of registrants (like eating breakfast and exercising), there is also tremendous variety in the registrants' weight management approaches.

Checking in with Amazon.com just now, I found 64,231 titles with the word, "diet" in them. And frankly, they probably all 'work.' Of course classic dieting, under-eating and over-exercising, while likely to lead you to a temporary result, is far less likely to get you into the Registry. Instead you need to actually like your life or you're very unlikely to keep living (or weighing) that way.

It's about living the healthiest life that you can enjoy, not the healthiest life that you can tolerate, because if your life is simply tolerable, you're not likely to keep living that way. To take an extreme example, while becoming a teetotaling, vegan, shut-in, marathon runner might well help you to manage your weight, is that a life you'd be willing, or even able, to live with forever?

Remember, too, that weight is a complex reflection of literally dozens of different variables. Some will indeed be within your control, while others won't. Therefore in regard to change, while I'm certain that there will be some things in your life that you can change to help manage your weight, I'm equally certain that there will be some things in your life, affecting your weight, that you either won't be able, or won't be willing, to change.

Consequently all of those numbers that come out of scales -- weight, body mass index, body-fat percentage -- none of them are particularly useful. I could use them to talk about your risk of developing weight-related medical conditions, but I don't bother, at least not in a counselling context as I don't find the fear approach to be helpful. You could use the numbers as calls to action -- to decide that you're going to do something. But what neither of us, and frankly no one should do, is use those numbers to set goals. The only goal that's fair to set is to live the healthiest life that you can enjoy.

Why?

Because there's simply no point in you trying to live a life you can't sustain. While you may not reach some table's definition of 'ideal,' is there anything other than weight in your life where you consider 'ideal' to be your goal? Why is it that every other area of your life you're rightfully proud and satisfied with your personal best? Why isn't your personal best good enough weight wise?

So what should you do? Whatever works for you. Whatever you can honestly see yourself doing for the rest of your life, and therefore the answer to the question as to whether Rebecca or I was right with our approach to dealing with mindless eating -- both of us and neither of us. The answer would all depend on the individual we were counselling.

If there were one right way, we'd all be doing it.

Dr. Yoni Freedhoff, MD is known as a "nutritional watchdog" for his advocacy efforts for improved public policies regarding nutrition and obesity. He is the founder and Medical Director of the Bariatric Medical Institute, dedicated to the (nonsurgical) treatment of overweight and obesity since 2004, and his personal website, Weighty Matters, is ranked among the world's top health blogs.